Establishment of reference intervals and transfusion criterion for Sonoclot analysis / 华中科技大学学报（医学）（英德文版）

Sonoclot analyzer has been widely used in many countries. But the reference intervals provided by the manufacturer were derived from only 45 participants, and there was no cut-off value for transfusion for Sonoclot analysis. This study aimed to establish reference intervals and transfusion criterion for Sonoclot analysis. Volunteers were recruited from healthy Chinese adults and patients undergoing cardiac surgery. Blood samples were withdrawn from forearm vein and measured for activated clotting time (ACT), clot rate (CR), platelet function (PF), activated partial thromboplastin time (APTT), fibrinogen concentration (FIB), and platelet count (PLT). The reference intervals were determined by the nonparametric method. Cut-off values were determined by the receiver operating characteristics curve. A total of 135 healthy volunteers and 281 patients were enrolled. The 95% reference intervals were 96-195 s, 22-51 signal U/min, >1.6 for ACT, CR, PF respectively. In the 281 patients, the results of APTT, FIB, PLT, ACT, CR, and PF ranged from 20.5-300.0 s, 0.28-4.11 g/L, (19.0-387.3)×109/L, 80-514 s, 2.9-74 signal U/min, and 0.1-5.1 respectively. The cut-off values for transfusion were >208, ≤14, and ≤1.3 for ACT, CR, PF respectively. The cut-off values of Sonoclot analysis were within the manufacturer's reference intervals, while they were outside the reference intervals established in this study. The results suggested that the manufacturer's reference intervals were not suitable for Chinese. The reference intervals and cut-off values established in this study will be helpful to Chinese patients.

Effects of blood loss during operation on coagulation function in selective non-cardiovascular surgery patients / 解放军医学杂志

Objective To investigate the change in coagulation function in relation to different amounts of blood loss in selective non-cardiovascular surgery patients.Methods Twenty American Anesthesia Association (ASA) class I or Ⅱ patients,aged 23-57 yr,undergoing non-cardiovascular surgery with normal preoperative coagulation were chosen randomly.After general anesthesia,on the basis of adequate sedation and analgesia,patients were given Ringer's solution and Voluven (pre-warmed to 37℃,volume ratio of crystalloid/colloid was 1:2) to maintain the stability of heart rate,blood pressure and central venous pressure.Temperature and blood gas analysis were monitored to prevent potential interference induced by hypothermia and acidosis.When the ratio of blood loss/blood volume reached 10%,15%,20% and 25%,all the routine blood components analysis and coagubility parameters,and Sonoclot coagulation and platelet function parameters were observed.Results Preoperative average value of Hct was 38.1%,and when ratio of blood loss/blood volume were 10%,15%,20 % and 25%,Hct was decreased to 33.4%,31.5%,30.1% and 27.9% respectively.When the ratio reached 15% or larger,platelet count decreased significantly compared with preoperative value (P